cocos 在原生中的 Imageloader

var urlPool = new Map();//预防文件多次下载
var cacheFileName = "cocosImageCache/";

function initLoader() {
    if (cc.sys.isNative) {
        var dirpath = jsb.fileUtils.getWritablePath() + cacheFileName;
        if (!jsb.fileUtils.isDirectoryExist(dirpath)) {
            //logUtil.logDebug("loadImage  1 loadNetImage !isDirectoryExist");
            if (jsb.fileUtils.createDirectory(dirpath)) {
                //logUtil.logDebug("loadImage  1 loadNetImage createDirectories success");
            } else {
                //logUtil.logDebug("loadImage  1 loadNetImage createDirectories failed");
            }
        } else {
            //logUtil.logDebug("loadImage  1 loadNetImage isDirectoryExist");
        }
    }
}

function load(sprite, defaultUrl, url) {
    if (!sprite) {
        //logUtil.logDebug("loadImage 1 load sprite == null");
        return;
    }
    //给该精灵加上url标签  防止复用时  异步多次回调  且回调顺序不一致的情况
    if (defaultUrl) {
        sprite.defaultUrlTag = defaultUrl;
    }
    if (!url) {
        if (defaultUrl) {
            //logUtil.logDebug("loadImage 1 load url == null");
            loadDefault(defaultUrl, sprite);
            return;
        } else {
            //logUtil.logDebug("loadImage 1 load url&&defaultUrl == null");
            return;
        }
    } else {
        sprite.urlTag = url;
        var img = cc.loader.getRes(defaultUrl);
        if (sprite.defaultUrlTag === defaultUrl) {
            if (!img) {
                //logUtil.logDebug("loadImage 1 load first load default sprite.defaultUrlTag != defaultUrl");
                loadDefault(defaultUrl, sprite);
            } else {
                sprite.spriteFrame = new cc.SpriteFrame(img);
            }
        }
    }
    if (url.startsWith("http")) {
        //logUtil.logDebug("loadImage 2 load http" + url);
        loadFromNet(url, sprite, defaultUrl);
    } else {
        //logUtil.logDebug("loadImage 2 load res" + url);
        loadWithOutFileCache(url, sprite);
    }
};

//是否第一次下载
function isFirstDownloading(url, sprite) {
    var sprites = urlPool.get(url);
    if (sprites) {
        sprites.push(sprite);
        //logUtil.logDebug("loadImage 1 isFirstDownloading sprite != null");
        return false;
    } else {
        var spArr = new Array();
        spArr.push(sprite);
        //logUtil.logDebug("loadImage 1 isFirstDownloading sprite == null");
        urlPool.set(url, spArr);
        return true;
    }
};

function getCacheArray(url) {
    var sprites = urlPool.get(url);
    return sprites;
};

function isFitTag(sprite, url) {
    if (!sprite) {
        return false;
    }
    return sprite.urlTag === url;
};

//比较缓存文件路径是否相同
function isFitFileTag(sprite, path) {
    if (!sprite) {
        return false;
    }
    var dirpath = jsb.fileUtils.getWritablePath() + cacheFileName;
    var filepath = dirpath + farmGame.util.Base64Encode(sprite.urlTag);
    return filepath === path;
};

//获取图片的格式  这里有个bug  微信头像没后缀  必须带上个后缀（不论后缀对不对）才能显示  cocos的bug
function getImageType(url) {
    if (isContains(url, 'jpg')) {
        return 'jpg';
    } else if (isContains(url, "webp")) {
        return 'webp';
    } else {
        return 'png';
    }
};

function isContains(str, substr) {
    return new RegExp(substr).test(str);
};

//不能单独使用
function loadFromNet(url, sprite) {
    if (cc.sys.isNative) {
        //logUtil.logDebug("loadImage  1 loadNetImage isNative" + url);
        // 如果是手机的jsb,走文件缓存
        var dirpath = jsb.fileUtils.getWritablePath() + cacheFileName;
        var filepath = dirpath + farmGame.util.Base64Encode(url);
        if (jsb.fileUtils.isFileExist(filepath)) {
            //文件存在
            //logUtil.logDebug("loadImage 2 loadNetImage load to memory cache" + url);
            loadWithTag(filepath, sprite);
            return;
        }
        //文件不存在 判断是否请求过 并将精灵加入回调队列
        if (isFirstDownloading(url, sprite)) {
            try {
                dowloadImage(url, sprite);
            } catch (error) {
                //logUtil.logDebug("loadImage 1 loadNetImage isFirstDownloading error" + error);
            }
        } else {
            //logUtil.logDebug("loadImage 10 loadNetImage already request " + url);
        }
    } else {
        //logUtil.logDebug("loadImage 11 loadNetImage  !isNative" + url);
        // 如果不是手机的jsb,直接加载
        loadWithOutFileCache(url, sprite);
    }
};

function isImageUrl(url) {
    if (url) {
        if (url.endsWith(".png") || url.endsWith(".jpg")) {
            return true;
        }
    }
    return false;
};

//不能单独使用
function loadWithTag(url, sprite) {//url全部为本地路劲
    //logUtil.logDebug("loadImage 1 loadWithTag load local resource" + url);
    if (url && isFitFileTag(sprite, url)) {
        //logUtil.logDebug("loadImage 2 loadWithTag load url fit" + url);
        var img = cc.loader.getRes(url);
        if (img) {//直接从内存缓存中取
            //logUtil.logDebug("loadImage 3 loadWithTag get cache from memory" + url);
            sprite.spriteFrame = new cc.SpriteFrame(img);
            return;
        }
        //logUtil.logDebug("loadImage 4 loadWithTag load url fit  not in memory cache" + url);
        cc.loader.load({url: url, type: getImageType(sprite.urlTag)}, function (err, texture) {
            if (err) {
                //logUtil.logDebug("loadImage 5 loadWithTag load local resource failed" + url);
                // loadDefault(defaultUrl, sprite);
                return;
            }
            if (isFitFileTag(sprite, url)) {//异步回调时 查看当前view是否变化了请求链接  在复用的时候会有问题
                //logUtil.logDebug("loadImage  6 loadWithTag isloaded ");
                sprite.spriteFrame = new cc.SpriteFrame(texture);
            } else {
                //logUtil.logDebug("loadImage 7 loadWithTag url is diffrent with sprite.urlTag");
            }
        });
    }
};

//直接请求不缓存//不能单独使用
function loadWithOutFileCache(url, sprite) {
    //logUtil.logDebug("loadImage 1 directLoadImage load local resource" + url);
    if (url) {
        var imgCache = cc.loader.getRes(url);//直接从内存缓存中取
        if (imgCache) {
            //logUtil.logDebug("loadImage 2 directLoadImage get cache from memory" + url);
            sprite.spriteFrame = new cc.SpriteFrame(imgCache);
            return;
        }
        cc.loader.load({url: url, type: getImageType(sprite.urlTag)}, function (err, texture) {
            if (err) {
                //logUtil.logDebug("loadImage 3 directLoadImage load local resource failed" + url);
                return;
            }
            if (url === sprite.urlTag) {
                //logUtil.logDebug("loadImage 2 directLoadImage isloaded" + url);
                sprite.spriteFrame = new cc.SpriteFrame(texture);
            } else {
                //logUtil.logDebug("loadImage 4 directLoadImage url is diffrent with sprite.urlTag");
            }
        });
    }
};

//不能单独使用
function loadDefault(defaultUrl, sprite) {
    //logUtil.logDebug("loadImage  1 loadDefault 1load default res" + defaultUrl);
    if (defaultUrl) {
        cc.loader.load({url: defaultUrl, type: 'png'}, function (err, texture) {
            if (err) {
                //logUtil.logDebug("loadImage 2 loadDefault load default res failed" + defaultUrl);
                return;
            }
            //logUtil.logDebug("loadImage 2 loadDefault isloaded" + defaultUrl + "defaultUrlTag" + sprite.defaultUrlTag);
            if (defaultUrl === sprite.defaultUrlTag ) {
                sprite.spriteFrame = new cc.SpriteFrame(texture);
            } else {
                //logUtil.logDebug("loadImage 2 loadDefault sprite.defaultUrlTag is not fit" + sprite.defaultUrlTag + "  " + sprite.urlTag);
            }
        });
    }
};

function doError(url) {
    try {
        // //logUtil.logDebug("loadImage 3 loadNetImage doError!!!!:" + "errorstr:" + errorStr + ":errorCode:" + errorCode + ":errInter:" + errorCodeInternal.toString());
        var cacheArr = getCacheArray(url);
        for (var k in cacheArr) {//
            var spritetmp = cacheArr[k];
            //logUtil.logDebug("loadImage 4 loadNetImage doError load default" + k + "spritetmp" + spritetmp);
            loadWithOutFileCache(spritetmp.urlTag, spritetmp);
        }
        //logUtil.logDebug("loadImage 5 loadNetImage doError delete " + url);
        urlPool.delete(url);
    } catch (error) {
        //logUtil.logDebug("loadImage 1 loadNetImage doError error" + error);
    } finally {
        urlPool.delete(url);
    }
};

function doSuccess(url) {
    try {
        //logUtil.logDebug("loadImage 6 loadNetImage doSuccess down success!!!!:");
        var cacheArr = getCacheArray(url);
        //logUtil.logDebug("loadImage 7 loadNetImage doSuccess down success!!!!cacheArr:" + cacheArr.length);
        for (var k in cacheArr) {//
            var spritetmp = cacheArr[k];
            var dirpath = jsb.fileUtils.getWritablePath() + cacheFileName;
            var filepath = dirpath + farmGame.util.Base64Encode(url);
            //logUtil.logDebug("loadImage 8 loadNetImage doSuccess load file to memory cache " + k + "url:" + url);
            loadWithTag(filepath, spritetmp);
        }
        //logUtil.logDebug("loadImage 9 loadNetImage doSuccess delete " + url);
    } catch (error) {
        //logUtil.logDebug("loadImage 1 loadNetImage doSuccess error" + error);
    } finally {
        urlPool.delete(url);
    }
};

function httpRequest(address, callback) {
    try {
        var xhr = new XMLHttpRequest();
        var self = this;
        xhr.onreadystatechange = function () {
            if (xhr.readyState == 4) {
                if (xhr.status >= 200 && xhr.status < 400) {
                    //logUtil.logDebug("loadImage 网络请求成功");
                    if (callback) {
                        //logUtil.logDebug("loadImage 回调开始");
                        callback(xhr)
                    } else {
                        //logUtil.logDebug("loadImage 回调失败 callback == null");
                    }
                } else {
                    //logUtil.logDebug("loadImage 网络请求失败" + xhr.status+" address:"+address);
                    doError(address);
                }
            } else {
                //logUtil.logDebug("loadImage 网络 请求状态变化" + xhr.status);
            }
        };
        xhr.timeout = 10000;
        xhr.onerror = function (err) {
            //logUtil.logDebug("loadImage 网络访问发生错误,请检查网络是否畅通22.");
            doError(address);
        };
        xhr.ontimeout = function () {
            // self.close(xhr);
            //logUtil.logDebug("loadImage 网络请求超时,请保证你的网络环境稳定.");
            doError(address);
        };
        xhr.responseType = "arraybuffer";
        xhr.open("GET", address, true);
        xhr.send();
    }catch (error) {
        //logUtil.logDebug("loadImage 1 网络请求错误 catch error" + error);
    } finally {
    }
};

function saveTemp(file_name, data) {
    return jsb.fileUtils.writeDataToFile(data, file_name)
};

function dowloadImage(url, sprite) {
    //logUtil.logDebug("loadImage 网络请求开始");
    httpRequest(url, function (xhr) {
        try{
            //logUtil.logDebug("loadImage 回调开始 start");
            var tmp_data = new Uint8Array(xhr.response);
            var dirpath = jsb.fileUtils.getWritablePath() + cacheFileName;
            //logUtil.logDebug("loadImage 回调 dirpath"+dirpath);
            var filepath = dirpath + farmGame.util.Base64Encode(url);
            //logUtil.logDebug("loadImage 回调 filepath"+filepath);
            var res = saveTemp(filepath, tmp_data)
            //logUtil.logDebug("loadImage 回调 存储"+res);
            if (res) {
                //logUtil.logDebug("loadImage 文件存储成功" + url+" filepath:"+filepath);
                doSuccess(url);
            } else {
                //logUtil.logDebug("loadImage 文件存储失败" + url+" filepath:"+filepath);
                doError(url);
            }
        }catch (error) {
            //logUtil.logDebug("loadImage 1 回调错误 catcherror" + error);
        } finally {
        }
    })
};

module.exports = {
    load: load,
    initLoader: initLoader,
}